Application Architecture

Possible layers:

• ui
• services
• dao
• domain

Artifacts

In SVN I have now created artifacts for the ebxml function. The following naming convention is used: [software name] - [architecture level name] - [function name]

aritifact name	responsibililty
geonetwork-domain-ebxml	Represents the domain model of the ebxml function.
geonetwork-dao-ebxml	Provides the dao layer for the function. A Dao can be used to do CRUD operations on domain objects towards the DB.
geonetwork-services-ebxml *)	Provides the service layer for the function. On this level everything is a offical transaction. This layer can also be exposed to any other technical protocol like Webservices, JMS, SMTP and so on. Fits well in a SOA architecture. Every service call will probably use one or more Dao's and will use heavily the domain.
geonetwork-web-ebxml	Provides the application layer of the application. The application layer interacts with the users of the webapplication. A user can be a browser or a machine. It parses the http request into a service call. The service call goes to the service layer.

*) not implemented yet. 

Considerations

• We could combine services and dao into one artifact named geonetwork-services-ebxml.
• We could call the dao artifact persistence.
• In my other project people are complaining about having more artifacts instead of one for the application. Indeed you need a powerfull computer and IDE. Personally I think that the advantages of more artifacts are greater than the disadvantages. For instance Hudson works on artifact level.